The present invention relates to an operator delivering a granular material such as sand from a fixed station to fill tanks commonly referred to as xe2x80x9csand boxesxe2x80x9d which are provided on rail vehicles, where the term xe2x80x9crail vehiclexe2x80x9d covers not only trains but also trams.
In rail vehicles, it is known to distribute sand between the wheels and the rail in order to increase adhesion between the wheel and the rail. When the vehicle is starting, and each time that it needs to deliver a large amount of torque, sand is taken from a storage tank referred to as a sand box. The sand box is filled when the vehicle is stationary, in particular when it is standing at a platform. The sand box has an inlet feed orifice which is accessible from outside the vehicle.
In general, sand boxes are filled from a sand storage vessel connected to a feed pipe. The storage vessel is positioned at a height which is sufficient to enable the sand to flow under gravity along the pipe into the inlet orifice of the sand box. In order to increase the flow rate of the sand, the storage vessel can be pressurized.
Proposals have already been made, in particular in documents DE 2 443 552 and EP 0 561 679 for devices to deliver a granular material that comprise both a transfer vessel for the material, which vessel is fed with compressed air under pressure, and a portable delivery head having one end connected by a flexible hose to the transfer vessel. The pressure and flow rate conditions for the compressed air in the transfer vessel are determined in such a manner that the flow of material in the hose corresponds to operation in xe2x80x9cdensexe2x80x9d phase for DE 2 443 552 and in xe2x80x9csolidxe2x80x9d phase for document EP 0 561 679.
The devices proposed in those prior documents are suitable for filling sand boxes having inlet orifices at man height, i.e. low enough for an operator standing on the platform to be able to insert the portable head manually into the inlet orifice of the sand box. Such devices are particularly suitable for the European railway network.
In contrast, those devices are not suitable for the North American railway network where rail vehicles are much larger in size with large-capacity sand boxes having their inlet orifices located at the tops of the vehicles so that they are not directly accessible to operators standing on a platform.
The object of the present invention is to enable a rail vehicle sand box to be filled when its inlet orifice is not directly accessible to an operator on a platform, with filling taking place via a portable delivery head connected to a pressurized vessel containing sand or other granular materials.
This object is fully achieved by the filler installation of the invention. In conventional manner, the installation comprises at least one pressurized vessel containing sand or other granular material and at least portable delivery head connected to said vessel.
In characteristic manner, said installation further comprises an intermediate assembly having a first end fitted with means for airtight connection to the portable delivery head and whose second end is connected to the sand box.
Thus, an operator on the platform can connect the portable delivery head to the first end of the intermediate assembly, this connection necessarily being airtight, and can then actuate the delivery head to feed sand into the intermediate assembly so that it goes to the inlet orifice of the sand box. The connection between the first end of the intermediate assembly and the delivery head must be airtight because sand is moved from the vessel to the sand box by means of the thrust applied thereto by the compressed air pressurizing the inside of the vessel. Any leakage of air through the connection means would cause the pressure to drop and would thus stop sand displacement from functioning properly.
In a manner that is known from document EP 0 561 679, the portable delivery head comprises both a rigid hollow tube for transferring sand and a suction nozzle which is fixed to the outside of the tube and which is connected to a suction source. Under such circumstances, the intermediate assembly comprises both an intermediate sand transfer pipe and an intermediate air suction pipe, the first ends of said pipes being fitted with means for airtight coupling respectively to the hollow tube and to the suction nozzle of the delivery head, while the second ends of said pipes are connected to the sand box. Below, in the present text, the term xe2x80x9cintermediate assemblyxe2x80x9d without further details covers, as appropriate, either a single intermediate pipe for transferring sand or else two intermediate pipes for transferring sand and for suction, respectively.
In an embodiment, the intermediate assembly is permanently mounted on the rail vehicle. The second end of the intermediate assembly opens out into the top portion of the sand box, either into its inlet orifice or else into a zone that is distinct from the inlet orifice of said sand box. In the second case, it therefore remains possible to fill the sand box in conventional manner under gravity from a storage vessel using the conventional inlet orifice, and also to fill the sand box under manual control of an operator using the portable delivery head and the intermediate assembly that are characteristic of the invention.
The first end of the intermediate assembly opens out laterally through a low portion of the rail vehicle. It can be advantageous to fit the vehicle so as to enable it to be filled regardless of which side of the vehicle is adjacent to the platform. For this purpose, the intermediate assembly includes at least one Y junction whose two upstream ends terminate in two first ends fitted with means for airtight coupling with the delivery head, said ends opening out laterally in respective opposite sides of the rail vehicle.
Some rail vehicles have two independent sand boxes disposed close to each other. Under such circumstances, the intermediate assembly may have at least one Y junction whose two downstream segments terminate in second ends connected to each of the two sand boxes, respectively.
In an embodiment of the filler installation of the invention, the intermediate assembly is permanently mounted on the platform.
Under such circumstances, the installation can include in particular a support gantry and means for fixing the intermediate assembly to the gantry, said gantry comprising a vertical girder fixed to the platform and a top horizontal girder; in addition, in this case, the downstream portion of the intermediate assembly is flexible.
In the first embodiment, all vehicles must be equipped with their own intermediate assemblies. In the second embodiment there is only a single installation and it serves to fill sand boxes via their conventional inlet openings. Nevertheless, this second embodiment presents the drawback whereby the operator must initially open the inlet orifice of the sand box and cause the second end of the intermediate assembly to penetrate therein. This therefore requires additional manual operation which is avoided with the first embodiment of the filler installation.
In a manner disclosed in document EP 0 561 679, the portable delivery head may comprise:
a) a first rigid tube for feeding sand;
b) a removable closure element for shutting the end of the first tube;
c) a shaft for pivoting the closure element, the shaft being mounted along the first tube; and
d) a handle for actuating said pivot shaft.
In a manner characteristic of the invention, the delivery head also comprises a support plate having the first tube and the pivot shaft passing therethrough; and the means for airtight coupling comprise means for fixing the support plate to the first end of the intermediate assembly.
Preferably, the first end of the intermediate assembly has a bearing plate which is pierced by an opening to pass the first tube and the removable closure element, the fixing means being suitable for providing releasable and airtight fixing of the support plate to the bearing plate.
When the intermediate assembly includes an intermediate pipe for sucking up dust and the portable delivery head includes a second rigid tube for sucking up dust, then the bearing plate has a second opening for passing the second tube, the first opening being disposed in register with the upstream end of the intermediate pipe for transferring sand, while the second end is placed in register with the upstream end of the intermediate suction pipe.
The fixing means can include, in particular, a gasket which is mounted on one of the two plates, on its face that faces the other plate.
In a particular embodiment, the fixing means may further comprise:
a) a quarter-turn clamping cam mounted free to rotate on the periphery of the support plate; and
b) a clamping lever secured to the cam, and the bearing plate may include a peripheral annular shoulder whose inside face is formed with a groove suitable for co-operating with the quarter-turn cam.
Thus, to connect the delivery head with the first end of the intermediate assembly, it suffices for the operator to cause the hollow tube(s) to penetrate into the opening(s) of the bearing plate until the support plate presses against the bearing plate, with the gasket optionally being interposed between said two plates, and then for the operator to actuate the clamping lever so as to cause the cam to turn through quarter of a turn, thereby obtaining airtight coupling between the delivery head and the intermediate assembly.